Struct MagneticModel 

pub struct MagneticModel { /* private fields */ }

A spherical-harmonic model of the main field: Gauss coefficients at an epoch and their linear secular variation, to degree 12.

Implementations

impl MagneticModel

pub fn name(&self) -> &'static str

The model’s name, as its coefficient file’s header gives it.

pub fn epoch_year(&self) -> f64

The epoch t₀ of the main-field coefficients, decimal year.

pub fn valid_until_year(&self) -> f64

The end of the model’s validity, decimal year.

pub fn field( &self, point: Geodetic, decimal_year: f64, ) -> Result<MagneticField, CoreError>

The magnetic elements at point (geodetic, on WGS 84, height above the ellipsoid) at time decimal_year (report, section 1.2, equations 7 to 20).

The geocentric components are

X′ = −Σₙ (a/r)ⁿ⁺² Σₘ (gₙᵐ cos mλ + hₙᵐ sin mλ) dP̆ₙᵐ(sin φ′)/dφ′
Y′ = (1/cos φ′) Σₙ (a/r)ⁿ⁺² Σₘ m (gₙᵐ sin mλ − hₙᵐ cos mλ) P̆ₙᵐ(sin φ′)
Z′ = −Σₙ (n + 1)(a/r)ⁿ⁺² Σₘ (gₙᵐ cos mλ + hₙᵐ sin mλ) P̆ₙᵐ(sin φ′)

turned by φ′ − φ into the geodetic frame: X = X′ cos(φ′ − φ) − Z′ sin(φ′ − φ), Y = Y′, Z = X′ sin(φ′ − φ) + Z′ cos(φ′ − φ). The rates are the same sums over ġ and ḣ.

At a pole the north and east directions follow the given longitude’s meridian, as the report’s section 1.4 sets them.

Errors

CoreError::Domain if point fails Geodetic::validated, if decimal_year is outside the model’s validity ([2025.0, 2030.0] for WMM2025) or not finite, or if the height is outside MIN_HEIGHT_M to MAX_HEIGHT_M.

Trait Implementations

impl Clone for MagneticModel

fn clone(&self) -> MagneticModel

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for MagneticModel

impl Debug for MagneticModel

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for MagneticModel

fn eq(&self, other: &MagneticModel) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for MagneticModel